Sr Software Development Engineer, Product Engineering – API Platform & Agentic AI

Workday•Pleasanton, CA

10d•Hybrid

About The Position

Workday is seeking a Sr Software Development Engineer for their Product Engineering team, focusing on API Platform & Agentic AI. This role is crucial for building the end-to-end product experiences that Workday customers use, many of which are now powered by agents and AI, relying on a strong API foundation. The engineer will operate across product pillars, working closely with Product Engineering teams and partner organizations to shape the API foundation, architecture, and operating model. The goal is to make it easy for Product Engineering to build agent-ready, high-quality APIs. This is a technical leadership role responsible for designing and delivering high-throughput, low-latency APIs and frameworks that support Workday's next generation of products and agents. The role involves shaping API design, driving performance and observability improvements, and coaching future senior engineers.

Requirements

8+ years experience in software development engineering, architecting, building, and scaling robust and efficient software systems.
5+ years experience in the following programming languages and technologies: TypeScript or Python.
Bachelor’s degree in Computer Science, Engineering, or related discipline, or equivalent practical experience.
Strong ability in Algorithmic Thinking, including advanced data structures and algorithms such as graphs, concurrent data structures, and caching/eviction strategies, to design and optimize solutions for complex API orchestration, request routing, and high-throughput workloads.
Solid experience with API Development, including REST, SOAP, and GraphQL, OpenAPI/Swagger-driven design, and experience in designing and building scalable, secure APIs and API integration patterns.
Strong understanding of Code Testing methodologies, such as contract testing, performance testing, and system/integration testing, and experience with advanced testing tools or frameworks (e.g., JUnit, ScalaTest, Postman, Mockito, and coverage tools such as Jacoco or Scoverage).
Strong understanding of Object-Oriented Design (OOD) principles like SOLID, domain-driven design concepts, and common architectural patterns (e.g., layered architecture, hexagonal architecture) and their application in designing scalable software architectures.
Solid understanding of Software Development principles and advanced development methodologies such as continuous delivery, trunk-based development, and test-driven or behavior-driven development.
Solid experience with Source Control Management (SCM) tools such as Git and advanced branching and merging strategies across multiple teams or services.
Proven ability to lead Team Collaboration within a software development team and mentor junior and mid-level engineers through design reviews, technical guidance, and knowledge sharing.
Strong skills in creating Technical Writing Documentation for comprehensive technical specifications, design documents, RFCs, and API and integration best-practice guides.
Experience leveraging AI‑assisted code generation and review tools (e.g., Cursor, Claude Code, GitHub Copilot) to improve development speed and quality.

Nice To Haves

Exposure to MCP or similar models is a strong plus.

Responsibilities

Lead design and implementation of APIs and platform features used by Product Engineering teams.
Champion consistent API standards, patterns, and tooling that align with cross-org guidance while solving concrete product needs.
Help Product Engineering teams expose capabilities via REST, GraphQL, and emerging integration patterns in a way that is friendly to agents and external consumers.
Lead end-to-end design and development of complex backend services and APIs.
Drive consensus with product managers, architects, and partner teams to define clear, evolvable API contracts and data models, using OpenAPI and internal standards.
Drive performance and scalability improvements, including latency optimization, capacity planning, and resiliency strategies for mission-critical product flows.
Design and implement observability for product APIs (metrics, tracing, structured logging), and use data to drive technical decisions and SLOs.
Collaborate on frameworks, tools, and patterns that make it simpler for other Product Engineering teams to define, publish, and maintain APIs.
Work with data platform teams to define patterns for exposing data safely and efficiently to API and agent workflows.
Provide technical leadership through design reviews, RFCs, spike investigations, and coaching junior engineers.
Participate in and improve on-call and incident response processes; own root cause analysis and long-term remediation for significant issues.
Act as a trusted technical partner to teams across Product Engineering, helping them make API and integration decisions.